I guess the confusing part was that I was testing the Thermistor on my work bench when I got that reading. Then I told you the temp on the display later on. No wonder it was increasing slightly on my work bench when I was holding it in my hand.
Mastertemp 400 cuts off
- Thread starter ParrishGuy
- Start date
I guess the confusing part was that I was testing the Thermistor on my work bench when I got that reading. Then I told you the temp on the display later on. No wonder it was increasing slightly on my work bench when I was holding it in my hand.
Yes, the temp increased from 72 to 73 after a few 55 second cycles. HOWEVER, I seem to have taken a step backwards. I tested the thermal regulater in a pot of hot water and it contracted as it should and went back to closed under cold water. When I reinstalled it now the heater will NOT ignite(this has never happend before) and the Fenwall has the error light flash twice and the service heater light came on.
I put together the 5 videos I took througout the day so you can see what I did. Its probably a 10 minute video so hopefully you guys stick with me
Thanks again for all the help.
Undo the unions on the check valve and see if it looks ok.
Does the pressure gauge go to 0 when the pump is off?
Does the pressure gauge go to 0 when the pump is off?
2 Flashes is Flame no call for heat.
Check the flame current DC microamps before call for heat and as the heater starts and runs.
Ok you sent me that procedure it’s the F- and F+ terminals on the Fenwal
I don't know what filter you have but assuming it's cartridge I'd remove them and try to run it that way to see if it'll change. Maybe a restrictive filter.
Check AC voltage from S1 to Ground and from S2 to ground before Call for Heat, during ignitor heat-up and during heating when in Flame Sense Mode.
Yes, in that youtube video I posted today I took the filter out and ran it and same cycling.
Ok, new day and less problems. I'm not sure what happened overnight but it's now back to igniting and cycling. Interesting thing is I timed the cycles and they started getting longer and longer before cutting off. I took the measurements you requested the best I could. See attached picture of everything written down.
Two questions..
1) Is there anywhere to check the exit temperature to see if that is whats causing it shut down?
2) It does heat my spa from 70 - 95 degrees in about 45 minutes even with the cycling. Is the cycling causing more propane to be used or it just a matter of taking a little longer to heat the spa as opposed to if it were running constantly?
Attachments
Are the S1 and S2 measurements from S1 to Ground and from S2 to ground?
What was the voltage from S1 to S2?
The DC voltage should be 2 to 7 volts.
Each micro-amp of flame current produces 1.0 VDC.
For example, 2.6 VDC equates to 2.6 µA.
Are you sure about the readings?
Measure before call for heat, during the 20 second ignitor heating phase and during heater operation.
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Which voltage setting did you use?
LoZ stands for Low Impedance (Z).
This feature presents a low impedance input to the circuit under test.
This reduces the possibility of false readings due to ghost voltages and improves accuracy when testing to determine absence or presence of voltage.
Most digital multimeters available today have an input impedance that's high enough to show the capacitively coupled voltage, giving a false impression of a live conductor.
The meter is actually measuring voltage coupled into the disconnected conductor.
However, these voltages, at times, can be 80-85% of what the "hard" voltage should be.
LoZ stands for Low Impedance (Z).
This feature presents a low impedance input to the circuit under test.
This reduces the possibility of false readings due to ghost voltages and improves accuracy when testing to determine absence or presence of voltage.
Most digital multimeters available today have an input impedance that's high enough to show the capacitively coupled voltage, giving a false impression of a live conductor.
The meter is actually measuring voltage coupled into the disconnected conductor.
However, these voltages, at times, can be 80-85% of what the "hard" voltage should be.
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You said check AC voltage S1 to ground and S2 to ground so those readings are AC. I did not check S1 to S2.
Do you want me to check S1 to S2 in DC or AC?
It just heated my 1,000 gallon spa from 70 to 100 in 45 minutes. Is that good?
User Manual - English_German_French_Spanish_Italian (1).pdf
drive.google.com
KAIWEETS HT208D 1000A AC/DC Inrush Clamp Meter
True-RMS Clamp Meter: Can accurately measure 1000 Amp AC/DC Current, 1000V AC/DC Voltage, Frequency, Duty Cycle, Resistance, Capacitance, Diode, Continuity, and Temperature. Easy to use for labs factories and households.
kaiweets.com
AC.
Do a High-Impedance voltage measurement and a Low-Impedance voltage measurement for S1 to Ground, S2 to Ground and S1 to S2 with no call for heat.
400,000 x 0.84 = 336,000 btu/hr.
1,000 gallons is 8,340 lbs.
336,000/8,340 = 40.3 degrees per hour or 0.67 degrees per minute.
(100 - 70)/45 = 0.67 degrees per minute, so exactly as expected.
The total amount of Propane should be about the same.
I still do not see why it is cycling.
There will usually be an error LED on the back of the circuit board or a red LED on the Fenwal or the water temp is going out of range.
When measuring Flame Current, measure from F+ to F- in DC volts or DC microamps.
Measure before call for heat, during heatup and as the heater is running.
Measure before call for heat, during heatup and as the heater is running.
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